Military and other covert air operations often desire or require non-visible runway lighting markers for nighttime operations. This has been achieved with small, man-portable, battery-operated lights that emit infrared light visible only to pilots or ground personnel wearing special goggles or in specially equipped aircraft. These lights are temporarily deployed on existing airstrips and runways, or are scattered about a likely spot to create a makeshift airway, drop zone or landing zone for a few hours.
While useful in the field, these deployable covert lights are less useful for fixed, permanent runway installations such as airports where several hours may be needed to set them up, where it is not desirable for the local civilian air traffic and ground personnel to see the deployed lights (including their setup), and where several hours may be needed to retrieve them. These deployable lights are also not suitable for extended, sophisticated, large-scale air operations where aircraft need to use them for sustained periods of time or spot them many miles away, and where detailed, large-scale, easily-adjusted covert lighting patterns may be needed around the airport.